San Diego has bike lanes everywhere where they're not needed, but as soon as you get to a narrow section of road or an intersection they disappear. It can easily add several miles onto a trip if you are unable to take the freeway. Many destinations are also build on the top of mesas, and because the place is so car-oriented things are spread out to a ridiculous degree.
I bike commute here, but it's maybe probably less practical or convenient than when I was commuting to downtown Pittsburgh or lower Manhattan. My commute would be nontrivial for someone of normal fitness & not much experience on a bicycle: 20 miles round-trip, 2000 feet of climbing, a portion along Interstate 5.
2000 vertical feet of hills or 2000 feet of cumulative elevation? That sounds like a lot for 10 miles, some of which is on I5... I gain only 800 feet total elevation and that's going 17 miles straight inland along the 56 from the Sorrento Valley station to the 15. For context, the Ramona pass is only 1853 feet above sea level.
I bike commute here, but it's maybe probably less practical or convenient than when I was commuting to downtown Pittsburgh or lower Manhattan. My commute would be nontrivial for someone of normal fitness & not much experience on a bicycle: 20 miles round-trip, 2000 feet of climbing, a portion along Interstate 5.